using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.Hosting;
using System;
using DotNetEnv;

namespace Inventory.Core
{
    /// <summary>
    /// Sets up application secrets from .env file in Development or HashiCorp Vault in Production.
    /// </summary>
    public static class EnvironmentBuilder
    {
        // Define the keys for your secrets
        private const string _dbConnectionString = "DB_CONNECTION_STRING";
        private const string _slurpitUrl = "SLURPIT_URL";
        private const string _slurpitApiKey = "SLURPIT_API_KEY";
        private const string _updateIntervalMinutes = "UPDATE_INTERVAL_MINUTES";

        /// <summary>
        /// Loads secrets into static properties based on the hosting environment.
        /// </summary>
        public static void SetupEnvironment(IHostEnvironment environment)
        {
            if (environment.IsDevelopment())
            {
                // In Development, load secrets from the .env file.
                Env.TraversePath().Load();
                
                // Assign to static properties
                Secrets.DbConnectionString = Environment.GetEnvironmentVariable(_dbConnectionString);
                Secrets.SlurpitUrl = Environment.GetEnvironmentVariable(_slurpitUrl);
                Secrets.SlurpitApiKey = Environment.GetEnvironmentVariable(_slurpitApiKey);

                int.TryParse(Environment.GetEnvironmentVariable(_updateIntervalMinutes), out var interval);
                Secrets.UpdateIntervalMinutes = interval > 0 ? interval : 60; // Default to 60 minutes
            }
            else
            {
                // In Production/Release, fetch secrets from Vault.
                // --- Provide your Vault details here ---
                // WARNING: For production, it's strongly recommended to use environment variables
                // or another secure configuration method instead of hardcoding the Vault URL.
                var vaultUrl = "http://your-vault-address:8200";
                var tokenPath = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.CommonApplicationData), "InventorySuite", "Vault", "vault-agent-token");
                var mountPath = "your-mount-path"; // e.g., "ihris-prod"
                var secretPath = "your-secret-path"; // e.g., "db_credentials"
                
                if (vaultUrl.Contains("your-vault-address") ||
                    mountPath.Contains("your-mount-path") ||
                    secretPath.Contains("your-secret-path"))
                {
                    throw new InvalidOperationException("Vault is not configured. Please update the hardcoded values in EnvironmentBuilder.cs before running in a non-development environment.");
                }
                
                try
                {
                    var vaultService = new VaultService(tokenPath, vaultUrl);
                    var secret = vaultService.GetSecret(mountPath, secretPath);
                    
                    // Assign to static properties from Vault
                    Secrets.DbConnectionString = vaultService.GetSecretValue(secret, _dbConnectionString);
                    Secrets.SlurpitUrl = vaultService.GetSecretValue(secret, _slurpitUrl);
                    Secrets.SlurpitApiKey = vaultService.GetSecretValue(secret, _slurpitApiKey);

                    int.TryParse(vaultService.GetSecretValue(secret, _updateIntervalMinutes), out var interval);
                    Secrets.UpdateIntervalMinutes = interval > 0 ? interval : 60; // Default to 60 minutes
                }
                catch (Exception ex)
                {
                    throw new InvalidOperationException("Failed to retrieve secrets from Vault.", ex);
                }
            }
        }
    }

    /// <summary>
    /// A static class to hold application secrets.
    /// </summary>
    public static class Secrets
    {
        public static string? DbConnectionString { get; set; }
        public static string? SlurpitUrl { get; set; }
        public static string? SlurpitApiKey { get; set; }
        public static int UpdateIntervalMinutes { get; set; }
    }
}